Galena Mineral | Uses and Properties Galena The primary ore of lead that is sometimes mined for its silver content Galena: Photograph of a nice cubic galena crystal with adjacent calcite crystals. The galena crystal is about two inches on a side. Collected from the Sweetwater Mine, Reynolds County, Missouri. Specimen and photo by Arkenstone / . What is Galena? Galena is a lead sulfide mineral with a chemical composition of PbS. It is the world's primary ore of lead and is mined from a large number of deposits in many countries. It is found in igneous and metamorphic rocks in medium- to low-temperature hydrothermal veins. In sedimentary rocks it occurs as veins, breccia cements, isolated grains, and as replacements of limestone and dolostone . Galena is very easy to identify. Freshly broken pieces exhibit perfect cleavage in three directions that intersect at 90 degrees. It has a distinct silver color and a bright metallic luster. Galena tarnishes to a dull gray. Because lead is a primary element in galena, the mineral has a high specific gravity (7.4 to 7.6) that is immediately noticed when picking up even small pieces.

Galena is soft with a Mohs hardness of 2.5+ and produces a gray to black streak . Crystals are common and they usually are cubes, octahedrons, or modifications. Structure of galena: Galena has a chemical composition of PbS. That means it contains an equal number of lead and sulfide ions. The ions are arranged in a cubic pattern that repeats in all directions. This structure is what causes crystals of galena to have a cubic habit and causes galena to break in three directions at right angles. Physical Properties of Galena Uses An ore of lead Argentiferous galena: Argentiferous galena from Coeur d'Alene, Idaho. Specimen is approximately 2-1/2 inches (6.4 centimeters) across. Argentiferous galena has a silver content that is often high enough for the galena to be mined as an ore of silver. Some galena mines receive more revenue from their silver than from their lead production. Argentiferous Galena - The Silver Ore The typical specimen of galena is about 86.6% lead and 13.4% sulfur by weight.

However, some specimens of galena contain up to a few percent silver by weight. They are called "argentiferous galena" because of their silver content. In these specimens, silver can substitute for lead in the atomic structure of the galena, or it can occur in tiny grains of silver minerals included in the galena. Silver within the galena disrupts the crystal structure, which often causes the galena to have curved cleavage faces. This tiny bit of knowledge can be a powerful prospecting tool. In addition to silver, galena can contain minor amounts of antimony, arsenic, bismuth, cadmium, copper , and zinc . Sometimes selenium substitutes for sulfur in galena. Cleavage fragments of galena: One of the most diagnostic properties of galena is its ability to break by cleavage in three directions that intersect at right angles. This forms cleavage fragments that are cubic and rectangular in shape. This photo shows pieces of crushed galena that clearly exhibit the right angle cleavage. This characteristic cleavage is caused by the mineral's cubic internal structure as shown above. Photo © iStockphoto / Tyler Boyes.

Galena value: Some mines produce more revenue from the silver content of their galena than from the lead content. Assume that we have a mine that produces argentiferous galena with an average composition of 86% lead, 13% sulfur and just 1% silver (as shown in the diagram on the left). If the silver price is $25 per troy ounce and the lead price is $1 per avoirdupois pound, the value of the lead in one ton of ore will be $1720, while the value of the silver in that same ton of ore will be $7292 (as shown in the diagram on the right). The small amount of silver has a huge impact on revenue because at the prices assumed, silver is 364 times more valuable than an equal weight of lead. It is easy to understand why mining companies get excited by argentiferous galena! Even though galena is the ore being removed and lead makes up the bulk of the product, these mines are often called "silver mines." Related: The Many Uses of Silver Smelting metals: Galena is one of the easiest ores to smelt.

It can simply be placed in a fire and then lead can be recovered from under the ashes when the fire goes out. Archaeologists have found evidence that lead was smelted as early as 6500 BC in what is now Turkey [1]. Small amounts of silver were refined from lead by the Romans about 2000 years ago [2]. Public domain image by Georgius Agricola . Smelting Galena Galena is very easy to smelt. If rocks that contain galena are placed in a fire, lead can be collected from below the ashes after the fire burns out. People have taken advantage of this simple smelting for thousands of years. Archaeologists have found lead beads and statues in Turkey that date back to about 6500 BC [1]. Lead is probably the first metal to have been processed from an ore. The ancient Romans made lead pipe and used it as indoor plumbing. (Plumbum is the Latin word for lead. The word "plumbing" and our use of "Pb" as the chemical symbol for lead come from the ancient Romans.) The ancient Greeks and Romans were able to separate silver from lead about 2000 years ago [2].

Many of the Roman lead ingots were inscribed "Ex Arg" or "Ex Argent" to signify that the silver had been removed from the lead. The Greeks were able to desilver lead to a 0.02 percent silver content and the Romans to a 0.01 percent silver content [3]. It is surprising that they were able to realize that the lead contained silver and amazing that they were able to develop such an efficient method of refining! Galena Information [1] Lead Fact Sheet : General Information and History, Stanford University, General Health and Safety Program, last accessed July 2016. [2] On the Nature of Metals (De Re Metallica): Georgius Agricola, 1556. Translated by Herbert Clark Hoover and Lou Henry Hoover, republished by Farlang.com. [3] Pliny the Elder on Science and Technology: John F. Healy, Oxford University Press, page 324, 1999. [4] 'Heavy Metal' Snow : Carolyn Jones Otten, press release of Washington University of St. Louis, February 2004. Alteration of Galena Galena weathers easily.

Fresh surfaces of galena tarnish rapidly from a silver metallic luster to a dull gray to dull black color. When exposed to the elements or buried in soil, galena quickly weathers to anglesite, cerussite, pyromorphite, or another lead mineral. These minerals are often used in prospecting. When they are found at the surface, they often reveal that galena is present below. Does It Really "Snow" Galena on Venus? The planet Venus has an inhospitable environment where volcanoes vent superheated gases into the atmosphere. Sulfur and lead are among the gases erupted from the volcanoes on Venus . They remain in the gaseous phase until they are high enough in the atmosphere to condense. In 2004, researchers at Washington University in St. Louis provided plausible evidence that "heavy metal snow" - which is most likely a combination of lead sulfide (galena) and bismuth sulfide - falls on the higher elevations of Venus [4]. Galena crystal radio: One of the most interesting uses of galena was in early crystal radios. The operation of these radios required alternating current to be converted into a pulsing direct current.

For that to occur, a semiconductor material was used to limit the flow of electricity to one direction. The alternating current flowed through a wire, known as a cat's whisker, into a semiconductor crystal, which was usually a crystal of galena, which only allowed flow in a single direction. Image © iStockphoto / Greg_H. Uses of Galena Galena is a very important mineral because it serves as an ore for most of the world's lead production. It is also a significant ore of silver. Galena has very few uses beyond its service as an ore, but that should not diminish its importance to society. The number one use of lead today is in the lead-acid batteries that are used to start automobiles. The typical auto battery contains about twenty pounds of lead and must be replaced every four or five years. There are billions of these batteries in the United States alone. Lead-acid batteries are also used as standby power supplies for computer networks, communication facilities, and other critical systems. Lead is also one of the metals used in energy storage systems associated with power generation and hybrid vehicles. The best way to learn about minerals is to study with a collection of small specimens that you can handle, examine, and observe their properties.

Inexpensive mineral collections are available in the Geology.com Store . Lead Safety Many uses of lead and lead compounds have been discontinued or significantly reduced over the past few decades in response to health concerns. Some of these uses include lead in residential paints, motor vehicle fuels, solder, ammunition, fishing weights, ceramic glazes, pesticides, cosmetics, glass, plastics, alloys and many other products. For this reason, many schools have removed galena from student mineral kits and have replaced it with a mineral with a lower level of concern. University of Minnesota’s Mineral Pages: Galena Usually, galena’s distinctive lead gray color, high specific gravity and cubic cleavage are enough to identify it, but at first glance there are a couple of minerals that might be mistaken for galena. Hematite: Hematite is a metallic mineral that can occur in many varieties. Some of the metallic varieties share a superficial appearance with galena, but the two can be distinguished by their streak and galena’s greater specific gravity. When a sample of hematite is rubbed across a rough hard surface, it leaves behind a characteristic red-brown streak, while samples of galena will leave a lead gray streak. Galena also feels much heavier than similar sized pieces of hematite.

Sphalerite: Galena and sphalerite commonly occur together and darker varieties of sphalerite may initially be confused with galena. Pure sphalerite samples can be distinguished from galena because they are harder (3.5 to 4) and have a lower specific gravity (3.9-4.1). The color of their streak provides an even simpler way to distinguish the two. A sample of galena rubbed across a rough, hard surface leaves a lead gray streak, while sphalerite’s streak is white to cream colored. Did you know... Galena is the most abundant lead mineral, has been mined for millennia, and remains our major source of that metal. It is a metallic, lead-gray mineral with cubic cleavage and a distinctly high density that makes galena samples feel much ‘heavier’ than expected for their size. Because it melts at a relatively low temperature and is so easily worked, lead was one of the first metals to be extensively used by many societies. Over centuries, lead use has led to the historic development of coins, bullets, batteries, televisions, and computers. Its use pervades past and present societies providing many benefits, but also raising some serious health issues.

Description and Identifying Characteristics Its perfect cubic cleavage, metallic luster, lead-gray color, and relative softness readily distinguish galena from most other metallic minerals. Perhaps its most distinctive feature though, is its very high density (high specific gravity). Samples of galena feel significantly heavier than similar-sized samples of most minerals, including other metallic minerals. The crystal structures of galena (PbS) and halite (salt or NaCl) are identical, so it is not surprising that the two exhibit similar perfect cubic cleavage. Both minerals will break along three directions of weakness that meet at right angles. Galena’s hardness is similar to that of a fingernail, so it is easily scratched by a nail or metal implement. ^ Top In Our Earth: The Geologic Importance of Galena The most common and widespread lead mineral, galena occurs in low-temperature to medium-temperature hydrothermal veins in igneous rocks, pegmatites, and contact-metamorphosed sedimentary rock. As a replacement mineral, galena can be found in sedimentary rocks, either disseminated throughout the rock or filling pore spaces and dissolved cavities in carbonate rocks.

Often found with other metallic ore minerals, such as pyrite, chalcopyrite, sphalerite, and marcasite, galena also occurs with more common vein minerals like quartz, calcite, fluorite, chert and dolomite. In North America, some of the most economically important galena deposits occur in altered carbonate and chert rocks of the Upper Mississippi River Valley area. ^ Top In Our Society: The Economic Importance of Galena The Roman naturalist Pliny may have been the first to record the use of the name ‘galena’ for lead ore. Galena (lead sulfide) is easily the most important source of lead, and often contains enough silver impurities that it is also a valuable source of that metal. Historically, its ready availability, high density, low melting point, and ease of working made lead one of the first metals to be extensively used by humans, with its known use dating back nearly 8,500 years. Lead was used as pipes in both the Egyptian and Roman worlds and for centuries has been used in glazes and pigments for ceramics and glass. In the more recent past, lead has been extensively used in the manufacture of bullets and was a common trade item on the American frontier.

As odd as it may seem though, lead has never been used in the manufacture of lead pencils. The ‘lead’ in pencils is actually a mixture of graphite and clay. Lead continues to be one of the most widespread, but least visible, metals in modern industrial societies. It is an important part of television screens and computer monitors, allowing people to safely watch the electronic pulses that form the backbone of modern communication. In the medical fields, lead also plays an important role as radiation shielding to minimize patients and staff exposure to X-rays. By far though, batteries account for most of the lead presently used in western society, comprising nearly four-fifths of the United States’ current domestic consumption. In the past, lead was also extensively used in paints, as the solder for food cans, and as an additive to gasoline, but many of these uses have been reduced or eliminated in western society because they can lead to dangerous levels of lead poisoning. Regrettably, this has not stopped western companies from continuing to promote these practices in less wealthy nations. ^ Top In Our Future: The Environmental Implications of Galena Use The past and present widespread use of lead in western society has had some serious environmental consequences.

Even ingesting small amounts of lead can cause brain damage or death, especially in very young children. Some researchers have argued that the Roman’s widespread use of lead for water pipes and eating utensils may have in part contributed to their civilization’s decline. More recently, the pervasive use of lead in gasoline, paint, and as solder for canned food resulted in widespread lead contamination throughout the northern hemisphere. In the 1950’s Claire Patterson, a geologist interested in determining the Earth’s age, first realized the extent of lead contamination in urban areas when he tried to develop a clean environment in which to measure the very small quantities of lead isotopes present in meteorite samples. Patterson later became a leader in the movement to ban the use of lead in gasoline, paint, and food packaging. The tangible results of this movement began with the Clean Air Act of 1970, which has since significantly reduced the levels of lead contamination American and European children are exposed to. Although leaded gasoline is no longer sold in Europe and North America, it is still extensively used in other areas and poses an increasing health threat.

Even within the United States, there are still many highly urban areas where residual lead contamination from past leaded gasoline use continues to pose a significant environmental risk for young children. ^ Top Galena in the Upper Midwest: Rich galena deposits in southwestern Wisconsin were responsible for the first significant wave of Euro-American immigration to that area in the early 1800’s. Early on in this Lead Rush, many miners lacked the time and materials to construct houses. They found it cheaper and faster to convert abandoned mines into crude dwellings. Visitors to the region began to call these miners ‘badgers’because they lived in underground ‘dens’. Later the name was extended to cover the entire ‘Badger State’. In Minnesota, galena deposits are only found in the southeastern counties of Fillmore and Olmstead, which together with southwestern Wisconsin form the northern extent of the Upper Mississippi lead-mining district. Minerals 1.3 • Sulfide minerals contain sulfur and a metal. • Common sulfide minerals include: galena and pyrite Galena Pronounce: • Galena has a composition of PbS.

• Galena is identified by its metallic, silvery gray luster; gray to dark gray streak; high specific gravity; and three perfect cleavages at 90 degrees. • Its hardness is 2.5. • Its specific gravity is 7.4 to 7.6. • Galena is a lead ore. It is used in television glass, auto batteries, solder, ammunition, and paint. Galena is a common lead ore. Notice how the samples are almost cubes. Galena is in the cubic crystal system. The right photograph shows a galena sample and its streak. Galena’s high specific gravity makes it feel especially heavy. Its specific gravity helps geologists to identify it. (Photograph by Parvinder Sethi) Pyrite Pronounce: • Pyrite has a composition of FeS2. • Pyrite is identified by its metallic luster; yellow to gold color; and dark gray to black streak. Cubic crystals are common in pyrite samples. • Its hardness is 6 to 6.5. • Its specific gravity is 5.0. • Pyrite is a sulfur ore. It is used in sulfuric acid, explosives, fertilizers, pulp processing, and insecticides.

Pyrite, also known as “fool’s gold,” is a sulfide mineral. It has a lower specific gravity than gold and a black streak. Real gold has a gold streak. (Photograph by Parvinder Sethi) Lead Smelting - Base Metal Smelting Base Metal Smelting Chemical Reactions of Lead Smelting BLAST FURNACE A major and primary Lead mineral is galena (chemical formula = PbS) which comprises of 86.6% of Lead [1]. In order to smelt this mineral, a blast furnace is needed to be used. A blast furnace is an enormous oven which is used to accomplish the smelting processes [2]. The process in which galena is smelted requires two important chemical reactions to occur within the furnace. 1) The galena is roasted (reacts with O2) in order to remove the sulfur component of the metal sulfide [2]. Roasting is a method where a sulfide ore (i.e an ore containing PbS) is heated in air which converts the metal sulfide to either a metal oxide or a metal itself [3].

Word Equation: Lead (II) Sulfide + Oxygen à Lead (II) Oxide + Sulfur Dioxide Chemical Equation: 2PbS + 3O2 à 2PbO + 2SO2 2) The newly formed Lead (II) Oxide subsequently reacts with coke to attain refined Lead [2]. Coke is a pure form of coal that contains carbon and is essential in the extraction of metals from their oxides [2]. Word Equation: Lead (II) Oxide + Carbon à Lead + Carbon Dioxide Chemical Equation: 2PbO + C à 2Pb + CO2 There is another process in which the galena mineral can be smelted through [4]. It also requires two chemical reactions to occur within the furnace. 1) Due to the sulfur content, carbon from the coke will not be able to reduce lead. Therefore, the mineral must be roasted to oxidize sulfur and create a metal oxide out of galena.

Word Equation: Lead (II) Sulfide + Oxygen à Lead (II) Oxide + Sulfur Dioxide Chemical Equation: 2PbS + 3O­­2 à 2PbO + 2SO2 2) Raw ore is then added to the products and is heated further. Word Equation: Lead (II) Oxide + Lead (II) Sulfide à Lead + Sulfur Dioxide Chemical Equation: 2PbO + PbS à 3Pb + SO2 REFERENCES: Ore minerals Short Courses IMPORTANT ORE MINERALS Most elements need to be concentrated into amounts that can be economically mined from ore deposits (usually hundreds to thousands of times their crustal abundance). This concentration is usually accomplished by dissolution of the element by hot water (hydrothermal ore deposits - gold, silver, lead), preferential crystallization from magmas (chromite deposits or pegmatites), surface weathering and leaching (aluminum, nickel, copper), or gravity separation of minerals during erosion (gold, diamonds, titanium). In the majority of cases there are only one or two minerals that provide all of a particular element for commercial uses.

Some elements in low concentrations (substituting in minor amounts for the major elements) are associated with minerals that are mined for other elements, but the shear volumes of materials that are processed result in a valuable byproduct (i e. elements associated with copper, lead, and zinc ores). Some elements are so valuable that almost any mineral containing that element in sufficient grades can be mined (gold, silver, platinum group). ELEMENTS Aluminum - The ore is mined from rocks that have been exposed to weathering in a tropical environment, bauxite. The main ore minerals in bauxite are gibbsite, bohmeite, and diaspore. Antimony - The primary ore of antimony is it's sulfide, stibnite. Arsenic - Recovered from other metal processing streams (primarily from the sulfosalts such as tennantite etc.). Arsenopyrite is the most common arsenic mineral. The relatively low demand for arsenic as compared to the amount of arsenic mined that is associated with other metals means it can be supplied from the waste streams of other ore processing. Barium - The chief source of barium is barite with minor production of witherite.

Beryllium - The major ore mineral for beryllium in the U.S. is bertrandite while worldwide the major source is from pegmatites that contain beryl. Bismuth - Primarily a byproduct of lead processing. Also found in a number of minerals such as bismuthinite and as a constituent in various sulfosalts. Boron - Chief source is playa lake deposits of borax, colemanite, kernite, ulexite. Bromine - Chief sources are brines from wells and Dead Sea. Cadmium - Unlike many other commodities cadmium is produced as a byproduct of zinc (sphalerite) mining. Cesium - The major ore mineral is pollucite, a pegmatite mineral. Production and use of this metal is extremely small (a few thousand kilograms per year). Chlorine - Produced from the mineral halite (rock salt). Chromium - The chief source is the mineral chromite which is found in large layered intrusives and serpentine bodies. Cobalt - The primary minerals for cobalt is cobaltite. Some cobalt is also produced from weathered tropical orebodies.

Columbium (see Niobium) Copper - Most copper ore bodies are mined from minerals created by weathering of the primary copper ore mineral chalcopyrite. Minerals in the enriched zone include chalcocite, bornite, djurleite. Minerals in the oxidized zones include malachite, azurite, chyrsocolla, cuprite, tenorite, native copper and brochantite. Gallium - A byproduct of zinc and alumina processing. Some primary "ore" may contain up to 200 ppm. Ga. Germanium - A byproduct of zinc ore processing. Also a deposit in China is associated with coal. Gold - The primary mineral of gold is the native metal and electrum (a gold-silver alloy). Some tellurides are also important ore minerals such as calaverite, sylvanite, and petzite. Hafnium - Primary ore mineral is zircon. Indium - Primarily is a byproduct of zinc processing. Iodine - Initial production was from seaweed. Iodine is extracted from natural gas field brines (up to 1200 ppm iodine in the brines).

Iron - Two major minerals in the production of iron are it's oxides, hematite and magnetite. These are found in preCambrian iron formations. Historically there was also production from goethite and siderite. The iron sulfides (pyrite and pyrrhotite) were not used as iron sources due to the difficulty of removing sulfur from the metals and the brittleness this sulfur caused in the metal. Lead - The primary ore mineral for lead is it's sulfide - galena. Some minor production from the past has come from secondary lead minerals - cerussite and anglesite. Lithium - The former primary ore minerals were pegmatite deposits of spodumene, lepidolite, and petalite, amblygonite. Currently the major U. S. production is from lithium carbonate brines. Magnesium - Although magnesium is found in many minerals, only dolomite, magnesite, brucite, carnallite, and olivine are of commercial importance. Magnesium and other magnesium compounds are also produced from seawater, well and lake brines and bitterns.

Manganese - The primary ores are oxides/hydroxides of manganese which include minerals such as hausmannite, pyrolusite, braunite, manganite, etc. and the carbonate, rhodochrosite. A large potential source is the deep sea manganese nodules. Mercury - The main ore is the sulfide, cinnabar. Molybdenum - The primary ore mineral is molybdenite. Nickel - The primary nickel ores are pentlandite, nickel bearing pyrrhotite and a weathering product, garnierite (a mixture of nÃ©pouite, pecoraite and willemseite). Niobium (Columbium) - The primary ore mineral is pyrochlore with minor columbite and tantalite-columbite. Phosphorus - Main ore minerals are in the apatite group of minerals (hydroxylapatite, fluorapatite, chlorapatite). Platinum group (Platinum, Osmium, Rhodium, Ruthenium, Palladium) - The primary ores are the native elements or alloys of the various elements or arsenides such as sperrylite.

They tend to occur in layered intrusives associated with chromite deposits. Potassium (potash) - The primary ore minerals are sylvite (primarily), brines, and langbeinite. Rare Earth elements (cerium, dysprosium, erbium, europium, gadolinium, holmium, lanthanium, lutetium, neodymium, praseodymium, samarium, scandium, terbium, thulium, ytterbium, yttrium) The major ore minerals containing rare earth elements are bastnasite, monazite, and loparite and the lateritic ion-adsorption clays. Major U.S. production of bastnesite is from Mountain Pass, California. Rhenium - Produced as a byproduct of molybdenite. Rubidium - Substitutes for potassium in lepidolite and pollucite. Production is small (a few thousand kilograms per year). Scandium (see Rare Earth) Galena: Galena mineral information and data. Galena Group . Galena is the primary ore mineral of lead.

Worked for its lead content as early as 3000 BC, it is found in ore veins with sphalerite, pyrite, chalcopyrite, tennantite-tetrahedrite, etc. and in skarns, as well as in sedimentary rocks where it may replace carbonate beds or be deposited in pore spaces. The crystals are bright when fresh but often tarnish after exposure to air. Classification of Galena Galena - Physical Properties & Healing Properties Galena Galena - Physical Properties & Healing Properties GALENA Uses: Major ore of lead and silver CLICK HERE To Purchase Kidz Rocks Galena Products. Specimens Click to view larger image Galena Galena & Calcite Galena is a common and popular mineral for rock hounds. Its characteristic cubes, distinctive cleavage and high density make it easy to identify and a favorite in high school geology labs. The structure of Galena is identical to that of halite, NaCl. The two minerals have the same crystal shapes, symmetry and cleavage. Some Galena may contain up to 1% silver in place of lead.

The large volume of Galena that is processed for lead produces enough Silver as a by product to make Galena the leading ore of Silver. Origin Of The Name The name Galena comes from the Latin word "galena" which means "lead ore". Interesting Facts Galena is by far the greatest ore of lead. Galena is the most common mineral containing lead, and contains mostly lead. Since the extraction process is so simple, lead has been extracted from Galena since the earliest times. To quote Allen N Wollscheidt, "Galena, back 75 years ago, was the stuff -- the crystal -- of crystal radio sets. Surely you have heard of these -- possibly your grand or great-grandparents built radio receivers out of round Quaker Oats boxes, a few feet of copper wire, a pair of headphones and a little "cats-whisker-with crystal" gadget from the hardware store. Some worked so well, they could be heard across the room. Galena is a natural semiconductor and so the forerunner, the enabler, of all the electronic gadgets we have today, from telephones to TVs to GPS navigating systems as well as all sorts of medical equipment -- in short, modern life as we know it.?

One of the oldest uses of galena was as kohl, which in Ancient Egypt, was applied around the eyes to reduce the glare of the desert sun and to repel flies, which were a potential source of disease. Galena was used as a solder used by the Romans for plumbing (the decline of the Roman empire is attributed to lead in the water supply!) Where Is It Found Galena deposits are found worldwide in various environments. Noted deposits include those at Freiberg, Saxony; Cornwall, The Mendips, Somerset, Derbyshire, and Cumberland, England; the Madan, Smolyan Province, Rhodope Mountains, Bulgaria; the Sullivan Mine of British Columbia; and Broken Hill and Australia. Galena also occurs at Mount Hermon in Northern Israel. In the United States, it occurs most notably in the Mississippi Valley type deposits of the Lead Belt in southeastern Missouri, and in the Driftless Area of Illinois, Iowa and Wisconsin. The economic importance of galena to the early history of the Driftless Area was so great that one of the towns in the region was named Galena, Illinois. What Do We Do With It Galena is the most important ore of lead. Silver is often produced as a by-product.

Most lead is consumed in making batteries, however, significant amounts are also used to make lead sheets, pipe and shot. It is also used to make low-melting-point alloys. Its use as a pigment has declined as has its use in making solder. Other uses include cable covering, plumbing, ammunition, manufacture of PbEt4 - an antiknock compound in petrol. Environmental concern with lead poisoning, (and cheaper unleaded petrol prices) is slowly resulting in less use of lead in petrol, the metal is very effective as a sound absorber, a radiation shield around X-ray equipment and nuclear reactors, used extensively in paints, although recently the use of lead in paints has been drastically curtailed to eliminate or reduce health hazards, the oxide is used in producing fine "crystal glass" and "flint glass" with a high refractive index for achromatic lenses, used to contain corrosive liquids, ammunition and insecticides. Metaphysical Uses Galena is a shinny gray stone with a cubic structure. Like its almost identical twin sister, pyrite, its physical appearance looks like little cubes stacked upon cubes, stacked upon cubes until a larger cube evolves. It is interesting to explore a sample with a magnifying glass.

There is no end to the number of images that can be found. Galena is very soft. It is possible to scratch or damage most galena samples with a hard fingernail. Galena is the principal ore of lead. In its natural state it should not be handled extensively with bare hands, as lead poisoning could result. Therefore, it is not a stone like quartz that you can hold for hours with only positive results. It should be touched and held for only a short period of time followed by washing your hands in soapy water. As long as it is within your aura, it will be effective. DO NOT use galena to make an elixir. Galena is a friend to those in turmoil. When your nervous energy is at a high level for any reason, it is the first stone to bring you to a place of rest. When a high state of stress is being experienced, you could use fluorite to smooth out the stress. But you will still have the same high level of energy. Obsidian calms the stress like fluorite and also lowers the energy level. Galena not only smoothes the stress, it absorbs this high level of negative energy almost completely.

This paves the way for centering of all of your systems, physical, emotional and spiritual. It helps to stabilize the mind and aids in refocusing your thoughts. It also calms and balances the nervous system. Galena teaches us acceptance of our limitations, and at the same time assists in the decrease of self-limiting ideas. Galena also stimulates the hair roots to promote thicker hair and helps to prevent hair loss. Galena should be cleansed frequently by exposure to sunlight. As we move toward the great transition, our vibrations, physical, mental and emotional, are being raised. Galena can be used to cope with this. It can bring us grounded calmness while at the peak of negative emotions, and can bring us away from panic attacks. Remember to keep your physical contact with Galena to a minimum. It is very effective while it is in your aura. It can be kept in a leather pouch and worn around the neck. Physical Characteristics Color: Lead to silver gray sometimes with a bluish tint. Luster: Metallic to dull in weathered faces. Transparency: Crystals are opaque.

Crystal System: Isometric; 4/m bar 3 2/m Crystal Habits: The cube, octahedron and combinations of the two. Spinel twinning is possible forming flattened crystals. Also massive and granular. Cleavage: Perfect in four direction forming cubes. Fracture: Uneven and rarely seen because of the perfect cleavage. Hardness: 2.5+ Specific Gravity: Approximately 7.5+ (heavy even for metallic minerals) Streak: Lead gray Associated Minerals: Calcite, dolomite, sphalerite, pyrite and other sulfide minerals, also lead oxidation minerals such as cerussite and anglesite. Other Characteristics: Brighter metallic luster on cleavage surfaces than on crystal faces. Best Field Indicators: Crystal habit, cleavage and, perhaps most importantly, density. Educational Videos Geologist Teaching Children About Galena Museum Quality Pyrite Marcasite Stalagmite Galena Mine IL 1934 Bureau of Mines Movie kjs crystal radio, steelgalena Back to Radio.. I have recently become interested in crystal radios and am especially interested in the "cystal" in the radio.

This is due to my background as a geologist / mineralogist / petrologist / oil exploration geologist. I have read in several radio websites concerning steel galena describing it as argentiferous as well as fine grained and useful as an excellent detector with numerous hot spots. While commonly associated with silver ores, I have never read of galena itself as being much silver bearing as a mineral. This puzzle sent me to the web to see what I could find on this "steel" variety. Steel Galena does indeed associate most closely with silver ore deposits, especially in the classic Rocky Mountain silver districts like Leadville in Colorado, Coeur d'Alene in Idaho, and Tintic / Park City of Utah. In all cases the ore bodies themselves are in sheared and altered sedimentary rocks. Mineralization is due to hydrothermal movements of water with movement aided by the sheared, and crushed zones having fine to extremely fine grain size, hence its name "steel".

To give a sense of the deposits themselves I wish to quote a couple accurate petrological descriptions: Waldschmidt, 1921: Hecla East Vein, Coeur d'Alene "The coarsest galena examined showed cleavage faces from 2 to 4 mm, square, but generally it is much finer grained than this. The fine-grained galena is commonly known as steel galena because freshly fractured surfaces have a steel-like luster. In all the specimens examed, this steel galena appeared to be in an intimate mixture of galena, tetrahedrite, sphalerite, pyrite, gnague, and other minerals present in the ore.".... "It appears that the original ore body consisted chiefly of galena, sphalerite, pyrite, pyrrhotite, tetrahedrite, freibergite, quartz and siderite. When movement took place along the O'Neil Fault and possibly along with minor slips, the ore body was greatly crushed, during which time the galena acted as a putty-like mass for the suspension of broken fragments of the harder minerals. This breaking resulted in the formation of the typical steel galena."....

In this ore, galena is NOT the silver-bearing mineral. Rather, the silver is in the freibergite and to a lesser extent in the tetrahedrite. Very interesting. Quoting from classic mineralogy texts on galena I find the following: Dana's Manual of Minerology: (Hurlbut) "Pb 86.6, S 13.4 per cent. Silver is usually present, probably as admixtures of silver minerals such as argentite or tetrahedrite." Elements of Mineralogy: (Mason and Berry) "Commonly, galena is very nearly pure PbS. The silver, arsenic, and antimony reported in chemical analyses are largely due to the inclusions of argentite of tetrahedrite, small amounts of which are difficult to detect in a black opaque mineral." An Introduction to the Rock Forming Minerals: (Deer, Howie and Zussman) "Substitution of other atoms for lead in galena is not very extensive. Among the elements which do accur in small amounts are: Sb, As, Bi, Ag, Ti, Zn, Cd, Fe, Mn and Cu.

In many cases these may be present in impurity minerals (acanthite Ag2S, sphalerite, chalcopyrite, etc.) rather than in the galena structure." Why is this interesting for the radio engineer? The following is my own theory, (speculation mostly). Most of you who have worked with galena detectors have noted that hot spots generally occur on or adjacent to fractures, lines or discontinuities on the crystal face, seldomly on the smooth lustrous face itself. Rectification occurs at the junction of two minerals, or of a mineral with a cat's whisker metal. Many explanations have been offered, most having to do with the position and nature of the crystal lattice at the point of contact, and the perceived presence of "impurities" (atoms other than lead) in the galena crystal matrix. As noted above, "Steel Galena" is a often an ore of silver containing not only galena, but abundant admixtures of associated minerals generally too small to see and thus seldomly described except in detailed mining reports as above. In addition, the very small grain size of common steel galena allows numerous physical and mineral discontinuities on the small detector surface area, and thus numerous hot spots.

I speculate that many/most of these hot spots may in fact be at the junctions of galena and other minerals along with the light contact of the ever-so-sharp cat's whisker itself. Other galena (lead) deposits such as the Missouri / Tri-State region are not associated with silver mineralization (Tri-State ores typically have only about 30ppm Ag). These show large museum quality crystal faces but have poor detector properties. Steel galena is difficult to find for sale due primarily to its lack of excellent crystal cleavage. Galena, as is well known, has beautiful LARGE crystal structure. Who would buy that ugly-looking grey junk? Kevin From Leadville Colorado, the specimens below are the best examples of "steel galena" I have yet come across. The samples have a dull weathered surface skin deep hiding a massive, fine-grained lead-silver mining ore of a classic Rocky Mountain type. On a fresh surface the sample has a fine texture and flat grey color. This is not museum material, and its difficult (to impossible) to locate on ebay, but its the real mccoy when it comes to crystal radio.

Don't even bother with the pretty pretty Missoury galena, it rightly belongs behind a glass display, not in a radio. Chips from this sample, potted in woods metal, rectifies strongly almost regardless of where the cat's whisker touches, instant sound. Steel Galena from the Tintic Mining District, a classic silver locality in Utah. (The excessively sparkally surface in the photo is from the flash.) Note also the presence of Anglesite alteration, (the clearish anglesite crystals separated from the galena by a dark finer grained almost greenish alteration zone). This is good radio material, but you may need hunt a bit more for hot spots than the finer-grained stuff above. Education and Resources - The Lead Mining Museum Education and Resources Home > Education and Resources The Museum of Lead Mining’s aim is to preserve the heritage of this important lead mining region, which encompassed Wanlockhead and Leadhills. In order to achieve this, we provide a unique, entertaining and educational experience and we can tailor make our tours to suit your educational needs. We welcome a variety of groups from Schools, Universities, Corporate Days Out and Coach Tour Companies, just to name a few.

So why not get in touch with us and we can start your Wanlockhead Experience… Galena Galena [PbS] or lead sulphide is the main source of lead [Pb]. It is widespread in the district and is found along with the common vein minerals such as quartz, calcite, barytes and dolomite. Galena has been the most important commercial mineral found in the locality. It was the basis of the Lead Mining industry which was of economic significance, especially during the 18th and 19th Centuries. The Galena crystal group on the left, is an example which was found at Leadhills in the Glengonnar Mine. Galena is the natural mineral form of lead sulfide. It is the most important lead ore mineral.Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms. It is often associated with the minerals sphalerite, calcite and fluorite. Lead Ore Deposits Galena deposits often contain significant amounts of silver as included silver sulfide mineral phases or as limited solid solution within the galena structure.

These argentiferous galenas have long been the most important ore of silver in mining. In addition zinc, cadmium, antimony, arsenic and bismuth also occur in variable amounts in lead ores. Selenium substitutes for sulfur in the structure constituting a solid solution series. The lead telluride mineral altaite has the same crystal structure as galena. Within the weathering or oxidation zone galena alters to anglesite (lead sulfate) or cerussite (lead carbonate). Galena exposed to acid mine drainage can be oxidized to anglesite by naturally occurring bacteria and archaea, in a process similar to bioleaching. Galena deposits are found in Wales, Germany, France, Romania, Austria, Belgium, Italy, Spain, Scotland, Ireland, England, Australia, and Mexico. Noted deposits include those at Freiberg, Saxony; Cornwall,The Mendips, Somerset, Derbyshire, and Cumberland, England; the Sullivan Mine of British Columbia; and Broken Hill, Australia. Galena also occurs at Mount Hermon in Northern Israel. In the United States, it occurs most notably in the Mississippi Valley type deposits of the Lead Belt in southeastern Missouri, and in the Driftless Area of Illinois, Iowa and Wisconsin.

The economic importance of galena to the early history of the Driftless Area was so great that one of the towns in the region was named Galena, Illinois. Galena also was a major mineral of the zinc-lead mines of the tri-state district around Joplin in southwestern Missouri and the adjoining areas of Kansas and Oklahoma. Galena is also an important ore mineral in the silver mining regions of Colorado, Idaho, Utah and Montana. Of the latter, the Coeur d’Alene district of northern Idaho was most prominent. Galena is the official state mineral of the U. S. states of Missouri and Wisconsin.The largest documented single crystal of galena measured 25 x 25 x 25cm3. Galena Uses One of the earliest uses of galena was as kohl, which in Ancient Egypt, was applied around the eyes to reduce the glare of the desert sun and to repel flies, which were a potential source of disease.Galena is a semiconductor with a small bandgap of about 0.4 eV which found use in early wireless communication systems. For example, it was used as the crystal in crystal radio sets, in which it was used as a point-contact diode to detect the radio signals.

The galena crystal was used with a safety pin or similar sharp wire, which was known as a “cat’s whisker”. Making such wireless sets was a popular home hobby in the Britain during the 1930s. Derbyshire was one of the main areas where Galena was mined. Scientists that were linked to this application are Karl Ferdinand Braun and Sir Jagdish Bose. In modern wireless communication systems, galena detectors have been replaced by more reliable semiconductor devices, though silicon point-contact microwave detectors still exist in the market. Chalcopyrite Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical composition CuFeS2.It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green tinged black.On exposure to air, chalcopyrite oxidises to a variety of oxides, hydroxides and sulfates.

Associated copper minerals include the sulfides bornite (Cu5FeS4), chalcocite (Cu2S), covellite (CuS), digenite (Cu9S5); carbonates such as malachite and azurite, and rarely oxides such as cuprite (Cu2O). Chalcopyrite is rarely found in association with native copper. Identification Chalcopyrite is often confused with pyrite, although the latter has a cubic and not a tetragonal crystal system. Further, chalcopyrite is often massive, rarely crystalline, and less brittle. Chalcopyrite is also a darker yellow in color, with a greenish tinge and diagnostic greasy luster.Due to its color and high copper content, chalcopyrite has often been referred to as “yellow copper”. Chemistry Natural chalcopyrite has no solid solution series with any other sulfide minerals. There is limited substitution of Zn with Cu despite chalcopyrite having the same crystal structure as sphalerite.However, it is often contaminated by a variety of other trace elements such as Co, Ni, Mn, Zn and Sn substituting for Cu and Fe.

Se, Fe and As substitute for sulfur, and trace amounts of Ag, Au, Pt, Pd, Pb, V, Cr, In, Al and Sb are reported.It is likely many of these elements are present in finely intergrown minerals within the chalcopyrite crystal, for instance lamellae of arsenopyrite representing As, molybdenite representing Mo, etc Sphalerite Sphalerite ((Zn,Fe)S) is a mineral that is the chief ore of zinc. It consists largely of zinc sulfide in crystalline form but almost always contains variable iron. When iron content is high it is an opaque black variety, marmatite. It is usually found in association with galena, pyrite, and other sulfides along with calcite, dolomite, and fluorite. Miners have also been known to refer to sphalerite as zinc blende, mock lead, false galena and black-jack. The mineral crystallizes in the cubic crystal system. In the crystal structure, zinc and sulfur atoms are tetrahedrally coordinated. The structure is closely related to the structure of diamond. The hexagonal analog is known as the wurtzite structure.

The lattice constant for zinc sulfide in the zincblende crystal structure is 0.596 nm, calculated from geometry and ionic radii of 0.074 nm (zinc) and 0.184 nm (sulfide). It forms ABCABC layers. Its color is usually yellow,brown, or gray to gray-black, and it may be shiny or dull. Its luster is adamantine, resinous to submetallic for high iron varieties. It has a yellow or light brown streak, a hardness of 3.5 – 4, and a specific gravity of 3.9-4.1. Some specimens have a red iridescence within the gray-black crystals; these are called “ruby sphalerite.” The pale yellow and red varieties have very little iron and are translucent. The darker more opaque varieties contain more iron. Some specimens are also fluorescent in ultraviolet light. The refractive index of sphalerite (as measured via sodium light, 589.3 nm) is 2.37. Sphalerite crystallizes in the isometric crystal system and possesses perfect dodecahedral cleavage.

Gemmy, pale specimens from Franklin, New Jersey are highly fluorescent orange and/or blue under longwave ultraviolet light and are known as cleiophane, an almost pure ZnS variety. Crystals of suitable size and transparency have been fashioned into gemstones, usually featuring the brilliant cut to best display sphalerite’s high dispersion of 0.156 (B-G interval)—over three times that of diamond. Freshly cut gems are lively with an adamantine luster and could conceivably be mistaken for a fancy-colored diamond in passing, but due to sphalerite’s softness and fragility the gems are best left unset as collector’s or museum pieces (although some have been set into pendants). Collectors may pay a premium for stones over one carat (200 mg), as clean crystals are usually quite small. Gem-quality material is usually a yellowish to honey brown, red to orange, or green; the two most important sources are the Chivera mine, Cananea, Sonora, Mexico; and the Picos de Europa, Cordillera Cantabrica, near Santander on Spain’s northern coast.

Gold The chemical symbol for gold is Au, from the Latin aurum, which means ‘shining dawn’. Aurora was the Roman goddess of dawn which links to the warm, yellow colour of gold. Gold and Copper are the only two non white coloured metals. Gold and copper were the first metals to be discovered by man, around 5000BC, and together with silver these three metals are found in the metallic state in the earth’s crust. Gold is still mined in its metallic form in over 60 countries around the world. Gold is referred to as a precious and a noble metal. Gold has an excellent chemical stability with a high resistance to corrosion and oxidation. However, this is just one of the many properties that gold possesses, which when considered in combination with each other have led to a number of exciting and often unique industrial applications. The purity of gold is measured in Carats. A Carat was originally a unit of mass (weight) based on the Carob seed or bean which was used by ancient merchants in the Middle East. The Carat is still used for the weight of gem stones where 1 carat = 200mg.

For gold is is used to measure the purity where pure gold is 24 carats. The following table shows the range from pure gold at 24 Carats to less pure at 9 Carats. Carats

Question: Galena is a major ore of which metal?
Answer: LEAD